[PATCH v2 0/6] irda: Use ktime_t instead of timeval

[PATCH v2 0/6] irda: Use ktime_t instead of timeval

[Chunyan Zhang]

This patch-set removed all uses of timeval and used ktime_t instead if
needed, since 32-bit time types will break in the year 2038.

This patch-set also used the ktime_xxx functions accordingly.
e.g.
* Used ktime_get to get the current time instead of do_gettimeofday.
* And, used ktime_us_delta to get the elapsed time directly.

Chunyan Zhang (6):
  irda: Removed all unused timeval variables
  irda: ali-ircc: Replace timeval with ktime_t
  irda: irda-usb: Replace timeval with ktime_t
  irda: nsc-ircc: Replace timeval with ktime_t
  irda: stir4200: Replace timeval with ktime_t
  irda: vlsi_ir: Replace timeval with ktime_t

 drivers/net/irda/ali-ircc.c    |   11 +++-------
 drivers/net/irda/ali-ircc.h    |    5 ++---
 drivers/net/irda/au1k_ir.c     |    3 ---
 drivers/net/irda/irda-usb.c    |   10 ++-------
 drivers/net/irda/irda-usb.h    |    5 ++---
 drivers/net/irda/kingsun-sir.c |    3 ---
 drivers/net/irda/ks959-sir.c   |    3 ---
 drivers/net/irda/mcs7780.c     |    2 --
 drivers/net/irda/mcs7780.h     |    1 -
 drivers/net/irda/nsc-ircc.c    |    7 ++----
 drivers/net/irda/nsc-ircc.h    |    5 ++---
 drivers/net/irda/stir4200.c    |   16 ++++++--------
 drivers/net/irda/via-ircc.h    |    4 ----
 drivers/net/irda/vlsi_ir.c     |   46 ++++++++++++----------------------------
 drivers/net/irda/vlsi_ir.h     |    2 +-
 15 files changed, 34 insertions(+), 89 deletions(-)

-- 
1.7.9.5

[PATCH v2 1/6] irda: Removed all unused timeval variables

[Chunyan Zhang]

In the file au1k_ir.c & via-ircc.h, there were two unused definitions of the
timeval type members, this commit therefore removes this unneeded code.

In other three files, the same problem is the rx_time member is only ever 
written, never read, so removed it entirely.

Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/net/irda/au1k_ir.c     |    3 ---
 drivers/net/irda/kingsun-sir.c |    3 ---
 drivers/net/irda/ks959-sir.c   |    3 ---
 drivers/net/irda/mcs7780.c     |    2 --
 drivers/net/irda/mcs7780.h     |    1 -
 drivers/net/irda/via-ircc.h    |    4 ----
 6 files changed, 16 deletions(-)

diff --git a/drivers/net/irda/au1k_ir.c b/drivers/net/irda/au1k_ir.c
index e151205..44e4f38 100644
--- a/drivers/net/irda/au1k_ir.c
+++ b/drivers/net/irda/au1k_ir.c
@@ -24,7 +24,6 @@
 #include <linux/interrupt.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
-#include <linux/time.h>
 #include <linux/types.h>
 #include <linux/ioport.h>
 
@@ -163,8 +162,6 @@ struct au1k_private {
 	iobuff_t rx_buff;
 
 	struct net_device *netdev;
-	struct timeval stamp;
-	struct timeval now;
 	struct qos_info qos;
 	struct irlap_cb *irlap;
 
diff --git a/drivers/net/irda/kingsun-sir.c b/drivers/net/irda/kingsun-sir.c
index e638893..fb5d162 100644
--- a/drivers/net/irda/kingsun-sir.c
+++ b/drivers/net/irda/kingsun-sir.c
@@ -114,7 +114,6 @@ struct kingsun_cb {
 					   (usually 8) */
 
 	iobuff_t  	  rx_buff;	/* receive unwrap state machine */
-	struct timeval	  rx_time;
 	spinlock_t lock;
 	int receiving;
 
@@ -235,7 +234,6 @@ static void kingsun_rcv_irq(struct urb *urb)
 						  &kingsun->netdev->stats,
 						  &kingsun->rx_buff, bytes[i]);
 			}
-			do_gettimeofday(&kingsun->rx_time);
 			kingsun->receiving =
 				(kingsun->rx_buff.state != OUTSIDE_FRAME)
 				? 1 : 0;
@@ -273,7 +271,6 @@ static int kingsun_net_open(struct net_device *netdev)
 
 	skb_reserve(kingsun->rx_buff.skb, 1);
 	kingsun->rx_buff.head = kingsun->rx_buff.skb->data;
-	do_gettimeofday(&kingsun->rx_time);
 
 	kingsun->rx_urb = usb_alloc_urb(0, GFP_KERNEL);
 	if (!kingsun->rx_urb)
diff --git a/drivers/net/irda/ks959-sir.c b/drivers/net/irda/ks959-sir.c
index e6b3804..8e6e0ed 100644
--- a/drivers/net/irda/ks959-sir.c
+++ b/drivers/net/irda/ks959-sir.c
@@ -187,7 +187,6 @@ struct ks959_cb {
 	__u8 *rx_buf;
 	__u8 rx_variable_xormask;
 	iobuff_t rx_unwrap_buff;
-	struct timeval rx_time;
 
 	struct usb_ctrlrequest *speed_setuprequest;
 	struct urb *speed_urb;
@@ -476,7 +475,6 @@ static void ks959_rcv_irq(struct urb *urb)
 						  bytes[i]);
 			}
 		}
-		do_gettimeofday(&kingsun->rx_time);
 		kingsun->receiving =
 		    (kingsun->rx_unwrap_buff.state != OUTSIDE_FRAME) ? 1 : 0;
 	}
@@ -514,7 +512,6 @@ static int ks959_net_open(struct net_device *netdev)
 
 	skb_reserve(kingsun->rx_unwrap_buff.skb, 1);
 	kingsun->rx_unwrap_buff.head = kingsun->rx_unwrap_buff.skb->data;
-	do_gettimeofday(&kingsun->rx_time);
 
 	kingsun->rx_urb = usb_alloc_urb(0, GFP_KERNEL);
 	if (!kingsun->rx_urb)
diff --git a/drivers/net/irda/mcs7780.c b/drivers/net/irda/mcs7780.c
index e4d678f..bca6a1e 100644
--- a/drivers/net/irda/mcs7780.c
+++ b/drivers/net/irda/mcs7780.c
@@ -722,7 +722,6 @@ static int mcs_net_open(struct net_device *netdev)
 
 	skb_reserve(mcs->rx_buff.skb, 1);
 	mcs->rx_buff.head = mcs->rx_buff.skb->data;
-	do_gettimeofday(&mcs->rx_time);
 
 	/*
 	 * Now that everything should be initialized properly,
@@ -799,7 +798,6 @@ static void mcs_receive_irq(struct urb *urb)
 			mcs_unwrap_fir(mcs, urb->transfer_buffer,
 				urb->actual_length);
 		}
-		do_gettimeofday(&mcs->rx_time);
 	}
 
 	ret = usb_submit_urb(urb, GFP_ATOMIC);
diff --git a/drivers/net/irda/mcs7780.h b/drivers/net/irda/mcs7780.h
index b10689b..a6e8f7d 100644
--- a/drivers/net/irda/mcs7780.h
+++ b/drivers/net/irda/mcs7780.h
@@ -116,7 +116,6 @@ struct mcs_cb {
 	__u8 *fifo_status;
 
 	iobuff_t rx_buff;	/* receive unwrap state machine */
-	struct timeval rx_time;
 	spinlock_t lock;
 	int receiving;
 
diff --git a/drivers/net/irda/via-ircc.h b/drivers/net/irda/via-ircc.h
index 7ce820e..ac15255 100644
--- a/drivers/net/irda/via-ircc.h
+++ b/drivers/net/irda/via-ircc.h
@@ -29,7 +29,6 @@ this program; if not, see <http://www.gnu.org/licenses/>.
  ********************************************************************/
 #ifndef via_IRCC_H
 #define via_IRCC_H
-#include <linux/time.h>
 #include <linux/spinlock.h>
 #include <linux/pm.h>
 #include <linux/types.h>
@@ -106,9 +105,6 @@ struct via_ircc_cb {
 
 	__u8 ier;		/* Interrupt enable register */
 
-	struct timeval stamp;
-	struct timeval now;
-
 	spinlock_t lock;	/* For serializing operations */
 
 	__u32 flags;		/* Interface flags */
-- 
1.7.9.5

[PATCH v2 2/6] irda: ali-ircc: Replace timeval with ktime_t

[Chunyan Zhang]

The ali ircc driver uses 'timeval', which we try to remove in the kernel
because all 32-bit time types will break in the year 2038.

This patch also changes do_gettimeofday() to ktime_get() accordingly,
since ktime_get returns a ktime_t, but do_gettimeofday returns a
struct timeval, and the other reason is that ktime_get() uses
the monotonic clock.

This patch uses ktime_us_delta to get the elapsed time, and in this
way it no longer needs to check for the overflow, because
ktime_us_delta returns time difference of microsecond.

Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/net/irda/ali-ircc.c |   11 +++--------
 drivers/net/irda/ali-ircc.h |    5 ++---
 2 files changed, 5 insertions(+), 11 deletions(-)

diff --git a/drivers/net/irda/ali-ircc.c b/drivers/net/irda/ali-ircc.c
index 58f98f4..58ae11a 100644
--- a/drivers/net/irda/ali-ircc.c
+++ b/drivers/net/irda/ali-ircc.c
@@ -1462,17 +1462,12 @@ static netdev_tx_t ali_ircc_fir_hard_xmit(struct sk_buff *skb,
 		if (mtt) 
 		{
 			/* Check how much time we have used already */
-			do_gettimeofday(&self->now);
-			
-			diff = self->now.tv_usec - self->stamp.tv_usec;
+			diff = ktime_us_delta(ktime_get(), self->stamp);
 			/* self->stamp is set from ali_ircc_dma_receive_complete() */
 							
 			pr_debug("%s(), ******* diff = %d *******\n",
 				 __func__, diff);
-			
-			if (diff < 0) 
-				diff += 1000000;
-			
+
 			/* Check if the mtt is larger than the time we have
 			 * already used by all the protocol processing
 			 */
@@ -1884,7 +1879,7 @@ static int  ali_ircc_dma_receive_complete(struct ali_ircc_cb *self)
 			 * reduce the min turn time a bit since we will know
 			 * how much time we have used for protocol processing
 			 */
-			do_gettimeofday(&self->stamp);
+			self->stamp = ktime_get();
 
 			skb = dev_alloc_skb(len+1);
 			if (skb == NULL)  
diff --git a/drivers/net/irda/ali-ircc.h b/drivers/net/irda/ali-ircc.h
index 0c8edb4..c2d9747 100644
--- a/drivers/net/irda/ali-ircc.h
+++ b/drivers/net/irda/ali-ircc.h
@@ -22,7 +22,7 @@
 #ifndef ALI_IRCC_H
 #define ALI_IRCC_H
 
-#include <linux/time.h>
+#include <linux/ktime.h>
 
 #include <linux/spinlock.h>
 #include <linux/pm.h>
@@ -209,8 +209,7 @@ struct ali_ircc_cb {
 	
 	unsigned char rcvFramesOverflow;
 		
-	struct timeval stamp;
-	struct timeval now;
+	ktime_t stamp;
 
 	spinlock_t lock;           /* For serializing operations */
 	
-- 
1.7.9.5

[PATCH v2 3/6] irda: irda-usb: Replace timeval with ktime_t

[Chunyan Zhang]

The irda usb driver uses 'timeval', which we try to remove in the kernel
because all 32-bit time types will break in the year 2038.

This patch also changes do_gettimeofday() to ktime_get() accordingly,
since ktime_get returns a ktime_t, but do_gettimeofday returns a
struct timeval, and the other reason is that ktime_get() uses
the monotonic clock.

This patch uses ktime_us_delta to get the elapsed time, and in this
way it no longer needs to check for the overflow, because
ktime_us_delta returns time difference of microsecond.

Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/net/irda/irda-usb.c |   10 ++--------
 drivers/net/irda/irda-usb.h |    5 ++---
 2 files changed, 4 insertions(+), 11 deletions(-)

diff --git a/drivers/net/irda/irda-usb.c b/drivers/net/irda/irda-usb.c
index 48b2f9a..f6c9163 100644
--- a/drivers/net/irda/irda-usb.c
+++ b/drivers/net/irda/irda-usb.c
@@ -495,18 +495,12 @@ static netdev_tx_t irda_usb_hard_xmit(struct sk_buff *skb,
 		mtt = irda_get_mtt(skb);
 		if (mtt) {
 			int diff;
-			do_gettimeofday(&self->now);
-			diff = self->now.tv_usec - self->stamp.tv_usec;
+			diff = ktime_us_delta(ktime_get(), self->stamp);
 #ifdef IU_USB_MIN_RTT
 			/* Factor in USB delays -> Get rid of udelay() that
 			 * would be lost in the noise - Jean II */
 			diff += IU_USB_MIN_RTT;
 #endif /* IU_USB_MIN_RTT */
-			/* If the usec counter did wraparound, the diff will
-			 * go negative (tv_usec is a long), so we need to
-			 * correct it by one second. Jean II */
-			if (diff < 0)
-				diff += 1000000;
 
 		        /* Check if the mtt is larger than the time we have
 			 * already used by all the protocol processing
@@ -869,7 +863,7 @@ static void irda_usb_receive(struct urb *urb)
 	 * reduce the min turn time a bit since we will know
 	 * how much time we have used for protocol processing
 	 */
-        do_gettimeofday(&self->stamp);
+	self->stamp = ktime_get();
 
 	/* Check if we need to copy the data to a new skb or not.
 	 * For most frames, we use ZeroCopy and pass the already
diff --git a/drivers/net/irda/irda-usb.h b/drivers/net/irda/irda-usb.h
index 58ddb52..8ac389f 100644
--- a/drivers/net/irda/irda-usb.h
+++ b/drivers/net/irda/irda-usb.h
@@ -29,7 +29,7 @@
  *
  *****************************************************************************/
 
-#include <linux/time.h>
+#include <linux/ktime.h>
 
 #include <net/irda/irda.h>
 #include <net/irda/irda_device.h>      /* struct irlap_cb */
@@ -157,8 +157,7 @@ struct irda_usb_cb {
 	char *speed_buff;		/* Buffer for speed changes */
 	char *tx_buff;
 
-	struct timeval stamp;
-	struct timeval now;
+	ktime_t stamp;
 
 	spinlock_t lock;		/* For serializing Tx operations */
 
-- 
1.7.9.5

[PATCH v2 4/6] irda: nsc-ircc: Replace timeval with ktime_t

[Chunyan Zhang]

The nsc ircc driver uses 'timeval', which we try to remove in the kernel
because all 32-bit time types will break in the year 2038.

This patch also changes do_gettimeofday() to ktime_get() accordingly,
since ktime_get returns a ktime_t, but do_gettimeofday returns a
struct timeval, and the other reason is that ktime_get() uses
the monotonic clock.

This patch uses ktime_us_delta to get the elapsed time, and in this
way it no longer needs to check for the overflow, because
ktime_us_delta returns time difference of microsecond.

Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/net/irda/nsc-ircc.c |    7 ++-----
 drivers/net/irda/nsc-ircc.h |    5 ++---
 2 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/drivers/net/irda/nsc-ircc.c b/drivers/net/irda/nsc-ircc.c
index e7317b1..dc0dbd8 100644
--- a/drivers/net/irda/nsc-ircc.c
+++ b/drivers/net/irda/nsc-ircc.c
@@ -1501,10 +1501,7 @@ static netdev_tx_t nsc_ircc_hard_xmit_fir(struct sk_buff *skb,
 		mtt = irda_get_mtt(skb);
 		if (mtt) {
 			/* Check how much time we have used already */
-			do_gettimeofday(&self->now);
-			diff = self->now.tv_usec - self->stamp.tv_usec;
-			if (diff < 0) 
-				diff += 1000000;
+			diff = ktime_us_delta(ktime_get(), self->stamp);
 			
 			/* Check if the mtt is larger than the time we have
 			 * already used by all the protocol processing
@@ -1867,7 +1864,7 @@ static int nsc_ircc_dma_receive_complete(struct nsc_ircc_cb *self, int iobase)
 			 * reduce the min turn time a bit since we will know
 			 * how much time we have used for protocol processing
 			 */
-			do_gettimeofday(&self->stamp);
+			self->stamp = ktime_get();
 
 			skb = dev_alloc_skb(len+1);
 			if (skb == NULL)  {
diff --git a/drivers/net/irda/nsc-ircc.h b/drivers/net/irda/nsc-ircc.h
index 32fa582..7be5acb 100644
--- a/drivers/net/irda/nsc-ircc.h
+++ b/drivers/net/irda/nsc-ircc.h
@@ -28,7 +28,7 @@
 #ifndef NSC_IRCC_H
 #define NSC_IRCC_H
 
-#include <linux/time.h>
+#include <linux/ktime.h>
 
 #include <linux/spinlock.h>
 #include <linux/pm.h>
@@ -263,8 +263,7 @@ struct nsc_ircc_cb {
 
 	__u8 ier;                  /* Interrupt enable register */
 
-	struct timeval stamp;
-	struct timeval now;
+	ktime_t stamp;
 
 	spinlock_t lock;           /* For serializing operations */
 	
-- 
1.7.9.5

[PATCH v2 5/6] irda: stir4200: Replace timeval with ktime_t

[Chunyan Zhang]

The stir4200 driver uses 'timeval', which we try to remove in the kernel
because all 32-bit time types will break in the year 2038.

This patch also changes do_gettimeofday() to ktime_get() accordingly,
since ktime_get returns a ktime_t, but do_gettimeofday returns a
struct timeval, and the other reason is that ktime_get() uses
the monotonic clock.

This patch uses ktime_us_delta to get the elapsed time of microsecond.

Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/net/irda/stir4200.c |   16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/drivers/net/irda/stir4200.c b/drivers/net/irda/stir4200.c
index dd1bd10..83cc48a 100644
--- a/drivers/net/irda/stir4200.c
+++ b/drivers/net/irda/stir4200.c
@@ -40,6 +40,7 @@
 #include <linux/moduleparam.h>
 
 #include <linux/kernel.h>
+#include <linux/ktime.h>
 #include <linux/types.h>
 #include <linux/time.h>
 #include <linux/skbuff.h>
@@ -174,7 +175,7 @@ struct stir_cb {
 	__u8		  *fifo_status;
 
 	iobuff_t  	  rx_buff;	/* receive unwrap state machine */
-	struct timeval	  rx_time;
+	ktime_t		rx_time;
 	int		  receiving;
 	struct urb	 *rx_urb;
 };
@@ -650,15 +651,12 @@ static int fifo_txwait(struct stir_cb *stir, int space)
 static void turnaround_delay(const struct stir_cb *stir, long us)
 {
 	long ticks;
-	struct timeval now;
 
 	if (us <= 0)
 		return;
 
-	do_gettimeofday(&now);
-	if (now.tv_sec - stir->rx_time.tv_sec > 0)
-		us -= USEC_PER_SEC;
-	us -= now.tv_usec - stir->rx_time.tv_usec;
+	us -= ktime_us_delta(ktime_get(), stir->rx_time);
+
 	if (us < 10)
 		return;
 
@@ -823,8 +821,8 @@ static void stir_rcv_irq(struct urb *urb)
 		pr_debug("receive %d\n", urb->actual_length);
 		unwrap_chars(stir, urb->transfer_buffer,
 			     urb->actual_length);
-		
-		do_gettimeofday(&stir->rx_time);
+
+		stir->rx_time = ktime_get();
 	}
 
 	/* kernel thread is stopping receiver don't resubmit */
@@ -876,7 +874,7 @@ static int stir_net_open(struct net_device *netdev)
 
 	skb_reserve(stir->rx_buff.skb, 1);
 	stir->rx_buff.head = stir->rx_buff.skb->data;
-	do_gettimeofday(&stir->rx_time);
+	stir->rx_time = ktime_get();
 
 	stir->rx_urb = usb_alloc_urb(0, GFP_KERNEL);
 	if (!stir->rx_urb) 
-- 
1.7.9.5

[PATCH v2 6/6] irda: vlsi_ir: Replace timeval with ktime_t

[Chunyan Zhang]

The vlsi ir driver uses 'timeval', which we try to remove in the kernel
because all 32-bit time types will break in the year 2038.

This patch also changes do_gettimeofday() to ktime_get() accordingly,
since ktime_get returns a ktime_t, but do_gettimeofday returns a
struct timeval, and the other reason is that ktime_get() uses
the monotonic clock.

This patch uses ktime_us_delta to get the elapsed time of microsecond,
and uses div_s64_rem to get what seconds & microseconds time elapsed
for printing.

This patch also changes the function 'vlsi_hard_start_xmit' to do the
same things as the others drivers, that is passing the remaining time
into udelay() instead of looping until enough time has passed.

Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/net/irda/vlsi_ir.c |   46 +++++++++++++-------------------------------
 drivers/net/irda/vlsi_ir.h |    2 +-
 2 files changed, 14 insertions(+), 34 deletions(-)

diff --git a/drivers/net/irda/vlsi_ir.c b/drivers/net/irda/vlsi_ir.c
index ac39d9f..a0849f4 100644
--- a/drivers/net/irda/vlsi_ir.c
+++ b/drivers/net/irda/vlsi_ir.c
@@ -33,6 +33,7 @@ MODULE_LICENSE("GPL");
 /********************************************************/
 
 #include <linux/kernel.h>
+#include <linux/ktime.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/pci.h>
@@ -40,9 +41,9 @@ MODULE_LICENSE("GPL");
 #include <linux/netdevice.h>
 #include <linux/skbuff.h>
 #include <linux/delay.h>
-#include <linux/time.h>
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
+#include <linux/math64.h>
 #include <linux/mutex.h>
 #include <asm/uaccess.h>
 #include <asm/byteorder.h>
@@ -180,8 +181,7 @@ static void vlsi_proc_ndev(struct seq_file *seq, struct net_device *ndev)
 	vlsi_irda_dev_t *idev = netdev_priv(ndev);
 	u8 byte;
 	u16 word;
-	unsigned delta1, delta2;
-	struct timeval now;
+	s32 sec, usec;
 	unsigned iobase = ndev->base_addr;
 
 	seq_printf(seq, "\n%s link state: %s / %s / %s / %s\n", ndev->name,
@@ -277,17 +277,9 @@ static void vlsi_proc_ndev(struct seq_file *seq, struct net_device *ndev)
 	seq_printf(seq, "\nsw-state:\n");
 	seq_printf(seq, "IrPHY setup: %d baud - %s encoding\n", idev->baud, 
 		(idev->mode==IFF_SIR)?"SIR":((idev->mode==IFF_MIR)?"MIR":"FIR"));
-	do_gettimeofday(&now);
-	if (now.tv_usec >= idev->last_rx.tv_usec) {
-		delta2 = now.tv_usec - idev->last_rx.tv_usec;
-		delta1 = 0;
-	}
-	else {
-		delta2 = 1000000 + now.tv_usec - idev->last_rx.tv_usec;
-		delta1 = 1;
-	}
-	seq_printf(seq, "last rx: %lu.%06u sec\n",
-		now.tv_sec - idev->last_rx.tv_sec - delta1, delta2);	
+	sec = div_s64_rem(ktime_us_delta(ktime_get(), idev->last_rx),
+			  USEC_PER_SEC, &usec);
+	seq_printf(seq, "last rx: %ul.%06u sec\n", sec, usec);
 
 	seq_printf(seq, "RX: packets=%lu / bytes=%lu / errors=%lu / dropped=%lu",
 		ndev->stats.rx_packets, ndev->stats.rx_bytes, ndev->stats.rx_errors,
@@ -661,7 +653,7 @@ static void vlsi_rx_interrupt(struct net_device *ndev)
 		}
 	}
 
-	do_gettimeofday(&idev->last_rx); /* remember "now" for later mtt delay */
+	idev->last_rx = ktime_get(); /* remember "now" for later mtt delay */
 
 	vlsi_fill_rx(r);
 
@@ -858,9 +850,8 @@ static netdev_tx_t vlsi_hard_start_xmit(struct sk_buff *skb,
 	unsigned iobase = ndev->base_addr;
 	u8 status;
 	u16 config;
-	int mtt;
+	int mtt, diff;
 	int len, speed;
-	struct timeval  now, ready;
 	char *msg = NULL;
 
 	speed = irda_get_next_speed(skb);
@@ -940,21 +931,10 @@ static netdev_tx_t vlsi_hard_start_xmit(struct sk_buff *skb,
 	spin_unlock_irqrestore(&idev->lock, flags);
 
 	if ((mtt = irda_get_mtt(skb)) > 0) {
-	
-		ready.tv_usec = idev->last_rx.tv_usec + mtt;
-		ready.tv_sec = idev->last_rx.tv_sec;
-		if (ready.tv_usec >= 1000000) {
-			ready.tv_usec -= 1000000;
-			ready.tv_sec++;		/* IrLAP 1.1: mtt always < 1 sec */
-		}
-		for(;;) {
-			do_gettimeofday(&now);
-			if (now.tv_sec > ready.tv_sec ||
-			    (now.tv_sec==ready.tv_sec && now.tv_usec>=ready.tv_usec))
-			    	break;
-			udelay(100);
+		diff = ktime_us_delta(ktime_get(), idev->last_rx);
+		if (mtt > diff)
+			udelay(mtt - diff);
 			/* must not sleep here - called under netif_tx_lock! */
-		}
 	}
 
 	/* tx buffer already owned by CPU due to pci_dma_sync_single_for_cpu()
@@ -1333,7 +1313,7 @@ static int vlsi_start_hw(vlsi_irda_dev_t *idev)
 
 	vlsi_fill_rx(idev->rx_ring);
 
-	do_gettimeofday(&idev->last_rx);	/* first mtt may start from now on */
+	idev->last_rx = ktime_get();	/* first mtt may start from now on */
 
 	outw(0, iobase+VLSI_PIO_PROMPT);	/* kick hw state machine */
 
@@ -1520,7 +1500,7 @@ static int vlsi_open(struct net_device *ndev)
 	if (!idev->irlap)
 		goto errout_free_ring;
 
-	do_gettimeofday(&idev->last_rx);  /* first mtt may start from now on */
+	idev->last_rx = ktime_get();  /* first mtt may start from now on */
 
 	idev->new_baud = 9600;		/* start with IrPHY using 9600(SIR) mode */
 
diff --git a/drivers/net/irda/vlsi_ir.h b/drivers/net/irda/vlsi_ir.h
index f9119c6..f9db2ce 100644
--- a/drivers/net/irda/vlsi_ir.h
+++ b/drivers/net/irda/vlsi_ir.h
@@ -723,7 +723,7 @@ typedef struct vlsi_irda_dev {
 	void			*virtaddr;
 	struct vlsi_ring	*tx_ring, *rx_ring;
 
-	struct timeval		last_rx;
+	ktime_t			last_rx;
 
 	spinlock_t		lock;
 	struct mutex		mtx;
-- 
1.7.9.5

Re: [PATCH v2 0/6] irda: Use ktime_t instead of timeval

[David Miller]

From: Chunyan Zhang <zhang.chunyan@linaro.org>
Date: Thu,  8 Jan 2015 12:01:26 +0800

> This patch-set removed all uses of timeval and used ktime_t instead if
> needed, since 32-bit time types will break in the year 2038.
> 
> This patch-set also used the ktime_xxx functions accordingly.
> e.g.
> * Used ktime_get to get the current time instead of do_gettimeofday.
> * And, used ktime_us_delta to get the elapsed time directly.

Applied to net-next, thanks.